Epilepsy Laboratory

Research Projects

Human EEG analysis

With funding from The Wellcome Trust, UK, in 2003 we established a high-level EEG research unit and processed 600 patients and controls by the beginning of 2007. While the aim of this project was to determine if patients with a variety of neurological disorders exhibit disturbances of gamma EEG rhythms (30-100 Hz), we have now demonstrated in six paralysed, ventilated, awake subjects, that electrical activity from muscles normally contaminates electrical recordings from the scalp. Contamination is a potential problem from 20Hz and above and is much worse at frequencies above 30Hz and from electrodes situated around the skull base. In the central scalp, EMG contamination still occurs, but is very much less than basally, and does not occur below 35Hz.
Using data collected from patients and ‘normals’ and confining our attention to those areas of the scalp EEG that are not contaminated by EMG, we have revealed that generalised epilepsy is associated with a broad increase in EEG power to 35Hz. Unexpectedly, in the same study, we have shown that patients with migraine plus aura have decreases in EEG power. These findings point to different pathophysiological mechanisms for these two, sometimes co-existing, disorders.
Finally, using portable EEG recordings in individuals we previously demonstrated to have peaks of high frequency (gamma) EEG activity in the laboratory, we have now identified the same high frequency peaks throughout the day while people go about their daily lives.

Cell swelling participating in epileptogenesis in rat models of epilepsy

We previously found, using an electrical impedance method, that marked reductions in extracellular volume and increases in cell size, follow the systemic administration of the two different convulsant drugs. Additionally, accelerated increases in cell size occurred in close temporal relationship to epileptic activity, but are not associated with further changes in the EEG. This swelling, occurring immediately in advance of seizures, is very likely to be a critical step related to the immediate causation of seizures and we hypothesise the cell swelling to be swelling of astrocytes.
In 2010, we used intravenous water infusions to develop a model of controlled astrocyte swelling in readiness for testing the effect of swelling on seizure induction with intra-cortial injections of convulsants. The convulsant studies are now in progress.

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Updated July 2, 2011